Moment of torque The market is the economic contact method which is the basic content of Commodity Exchange. Under the condition of commodity economy, the premise of exchange generation and existence is social division of labor and commodity production. Because of the social division of labor, the different producers, respectively, engaged in the production of different products, did not meet the needs of themselves and others and exchange their respective product, so that the general labor products into commodities, make the product production is transformed into commodity production. It is under this condition that the market for goods to be exchanged to meet the needs of different producers is born. Therefore, the market is the product of the division of labor and the exchange of goods under the conditions of commodity economy. The market and commodity economy have inalienable internal relation. (3) monetary benefits -- increase the monetary value of assets. There are both measurable and unquantifiable benefits in these three different forms of income. Among them: mental income is too strong to measure, monetary gain is easy to measure because of the static concept of value change. Economists, therefore, focus only on actual earnings. In the late 19th and early 20th century, with the transition from free capitalism to monopoly capitalism, the factory itself had undergone complex and profound changes. Constantly adopt new technology to make the production rapid development; The scale of production keeps expanding, competition intensifies, and a large-scale monopoly enterprise is produced. The separation of rights and ownership and the formation of a professional management stratum; The scientific management system has been established, and a series of scientific management theories have been formed to make the enterprises mature and become modern enterprises. The accounting income follows the historical cost principle and the matching principle, which is conducive to the objective reflection of the business management responsibility of the enterprise management authorities. But, due to the historical cost principle inherent defects, especially according to the present value of revenue and expenses by historical cost line, makes the calculation of accounting earnings lack of inner logical unity, and the matching principle is difficult to carry out, so that the book value of assets can not reflect its real value, cost cannot be fully compensated. And the economic benefit is measured in the current value, which reflects the actual value of the asset, which is beneficial to the full compensation of the cost.